Gun having artillery training round of ammunition



0a. 28, 1953 w. c; NI HOLS 2,857,812

GUN HAVING ARTILLERY TRAINING ROUND 0F AMMUNITION Filed March 2, 1956 2 Sheets-Sheet 1 seal 7 do i z 24m N l l4- I, 5 1 I \KYY 12 12 FIG. l.

I I6 7/ I0 a! l8 2o 19 II I4 I 22 .3 5 a as c INVENTOR, :2- WILLIAM G. NICHOLS FIG. 2. b BY Tf-MLQiQQAJQ f VJL ATTORNEYS Get. 28, 1958 w. ca. NICHOLS 2,857,812

GUN HAVING ARTILLERY TRAINING ROUND OF AMMUNITION Filed March 2, 1956 2 Sheets-Sheet 2 FIG. 3

IN V EN TOR.

WILLIAM G. NICHOLS Y 4. y

i A! $.2Qw nmansvs GUNHAVING ARTILLERY TRAINING ROUND F AMIVIUNITION William G. Nichols, Los Angeles, Calif., assignor to the United States of America as represented by the Secretary of the Army Application March 2, 1956, Serial No. 569,211 6 Claims. (CI. 89-29) (Granted under Title 35, U. S. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes without payment of any royalty thereon.

This invention relates to a gun of the type inwhich simulated ammunition may be used for training purposes and in which a subcaliber tube is carried by said simulated ammunition. An object is to provide a gun of this type which is especially adapted for that phase of training in.which the simulated ammunition need not be removed from the gun but only subcaliber ammunition is added and after being fired the spent subcaliber cartridge case is extracted.

In guns of the foregoing type it has been customary to provide an inner door closing the subcaliber tube and carrying an extractor for a spent cartridge case after firing. There is also usually provided an outer door or breech block carryingan extractor to withdraw the simulated fixed ammunition. Where such fixed ammunition does not need to be extracted on each opening of the breech each time a spent subcaliber cartridge case has to be removed, some way of rendering the extractor carried by the breech block inoperative is necessary in order not to extract the dummy ammunition. Instead of resorting to a change in the breech block and its extractor, the change has been made in the simulated ammunition. Specifically, the usual base flange is interrupted for a short angular distance greater than the width of the extractor carried by the breech block so that when the training round of simulated ammunition is inserted in the gun in a given angular portion, the extractor carried by the breech block will not withdraw such dummy ammunition on opening the breech block. However, a spent subcaliber round will be at least partially withdrawn on opening the breech block. This is accomplished byhaving a projection on said inner door extend into the interruption in the base flange of the simulated ammunition so that this inner door will be at least partially opened in response to opening the breech block with the extractor carried thereby and a spent subcaliber. cartridge is extracted at least partially, by the opening of the inner door and its extractor. A positive lock is provided on the simulated ammunition to prevent its being withdrawn from a gun until such ammunition is unlocked.

This invention is an improvement upon the simulated ammunition and subcaliber tube of Bluford et 211., U. S. Patent No. 2,541,025 dated February 13, 1951, adapting the simulated ammunition for use where its removal is not to be expected frequently, and locking it within the gun enabling the extractors carried by the breech block to initiate extraction of a subcaliber cartridge without initiating extraction of the simulated ammunition.

Referring to the drawings, Fig. 1 is a longitudinal section on a horizontal plane through the rear end of a recoilless gun embodying this invention. Fig. 2 is a view corresponding to Fig. 1 but with the breech block partially open. Fig. 3 is an enlarged View of the inner door closing the subcaliber tube of Fig. l and without showing the surrounding gun parts. Fig. 4 is a longitudinal section on the line 44 of Fig. 1, i. e., a vertical longitudinal section through a gun embodying this invention.

Referring to Fig. 1 the gun tube 10 is of the type found in recoilless guns which are provided with the usual breech block 11 having a usual firing pin 12 and an extractor 13 carried by the breech block mechanism for extracting the spent fixed ammunition Within the gun tube. The outer door or breech block is pivoted at 14 and is rotated and then swung outwardly around its pivot as is customary in such guns. A closure block 15 contains the usual venturi openings through which gas issues to overcome the tendency to recoil. Instead of the usual fixed ammunition, the simulated ammunition 16 is shown in the gun and a subcaliber tube 17 is firmly secured within the dummy ammunition 16. An inner 7 door 18 closes the subcaliber tube and is pivoted at 19, there being an extractor 20 carried by the inner door 18 for initiating withdrawal of the subcaliber case 21 when spent.

The dummy ammunition 16 is provided with the usual rear end peripheral rim or flange 22. As shown in Fig. 3

this base flange 22 is interrupted for an angular distance greater than the width of a projection 23 on the door 18. Thus on opening the breech block in the customary 'manner the extractor 13 instead of engaging the dummy ammunition, engages the projection 23 for opening the door 18 as shown in Fig. 2 and initiates withdrawal of the spent cubcaliber cartridge case 21. The firing pin 24 for the subcaliber cartridge is shown in Fig. 1 as being of smaller diameter than the firing pin 12 in the breech block. The inner door 18 is held in closed position for subcaliber firing by the breech block 11. A hardened pin 12 is loosely held inside the firing spring 12". This pin is not normally a part of the weapon and is slightly longer than the compressed length of the spring 12 The chamber pressure developed in the subcaliber tube is several times that normally developed in the major weapon tube. As a result the subcaliber and major weapon firing pins 24 and 12 are driven to the rear with considerable force. If the pin 12 were not present, the major weapon firing pin 12 would, after repeated subcaliber firing, flatten and deform firing spring 12 until its replacement would become necessary.

To prevent withdrawal of the dummy ammunition 16 during training in use of the subcaliber ammunition, Fig. 4 shows how the rear end of the dummy ammunition is provided with locking cams 25 provided with locking projections 26 engaging the closure block 15 to prevent withdrawal of the dummy ammunition. The ends 27 of the locking earns 25, which are substantially flush with the rear end of the dummy ammunition, are provided with hexagonal recesses in which a suitable Wrench is inserted for turning the locking cams 25 and rotating the projections 26 from the locking position illustrated in Fig. 4 to a position in which the locking projections 26 are radially within the outer diameter of the fixed ammunition 16, in order that when required the dummy ammunition may be withdrawn from the gun. A threaded and pointed pin 30 engages some one of several longitudinal shallow grooves 31 for the purpose of locking the subcaliber tube against any change in headspace. Adjustment of this pin until its point is clear of a groove 31 allows for adjustment of the headspace without disassembly of the device. By headspace is meant that space between the rear end of the cartridge and the breech block or door 18 with the substantially flush inner end of the firing pin 24.

In Fig. 3 is shown a spring for closing the inner door 18, this spring having its outer ends 28 engaging the rear wall of the dummy ammunition while its mid-portion 29 cooperates with the door 18 to efiect closing thereof.

Patentedoct. 28, 1958' Such a self-closing door is desirable in order that the inner door'18'may be always closed and not held open when the breech block is being closed. This avoids the possibility of damage to the inner door 18 by the heavier breech block 11. Among'the advantages of this invention may be mentioned the extraction of the spent subcaliber cartridge case 21. by opening the breech block, at least the extraction of this'spent subcaliber case is initiated so that it will not be'stuck within the subcaliber tube 17. Ejection is accomplished manually. The locks 25 for the dummy ammunition prevent its being withdrawneven if the subcaliber tube were not properly positioned angularly within the gun to have the ejector 13 engage the projection 23' on the door 18. Heretofore the use of a preengraved rotating band on a support for a subcaliber tube has not been always accurate due'to wear in said support and in the bore of 'the primary weapon. In this construction screws 32 spaced 120 or 180" apart provide a more accurate positioning means for the subcalibertube'17. The screws have a twofold function. The primary purpose of screws 32 is to provide a means for preventing the dummy ammunition from rotating in the bore of the main weapon, in place of or in addition to the use of a preengravedrotating band. By proper shimming under the heads of these screws 32, a very tight fit in the bore of the main gun canbe obtained for accurately aligning the subcaliber tube axis with that of the primary weapon 'having rifiing, not shown, inwhich the heads of screws are received. One or more screws 34 have been found useful to prevent any angular displacement between the dummy cartridge case 16 and the front end portion 33 ofthe dummy ammunition. Likewise screws 35 prevent angular displacement between the subcaliber tube 17 and the front end portion 33.

I claim:

1. In a gun having a bore, a breech block pivoted to said gun for closing said bore, a first firing pin and a first extractor carried by said breech block, simulated fixed ammunition arranged for insertion in said bore when said breech block is'open and arranged for independent movement of said first extractor, a subcaliber tube within said simulated fixed ammunition, a door pivoted'to'and within a rear end portion of said simulated ammunition for closing said subcaliber tube where subcaliber ammunition has been inserted in said tube,

a second firing pin within said door and arranged to be moved in response to movement of said first firing pin, an extractor for subcaliber ammunition, said lastmentioned extractor being carried by said door, and a pivotal mounting for said door, the pivotal mounting for said' breech block being widely displaced angularly from the pivotal mounting'for said door, the combination therewith of the improvement for adapting said gun to training usewhen said simulated ammunition is not to be removed. between subcaliber firings, said improvement including a lock carried by said simulated ammunition for retaining the same within said gun against being withdrawn by said extractor carried by said breech block,

said simulated ammunition being provided with a usual 6 base flange against which the extractor carried by said breech block 'may engage in withdrawing it from the gun, and said base flange being interrupted for an angular distance greater than the thickness of said extractoncarried by the breech block, whereby when said simulated ammunition is angularly disposed to have the interruption in its base flange coincide with said extractor carried by said breech block, said last-mentioned extractor will not eject said simulated ammunition but will initiate extraction of said subcaliber spent ammunition.

2. A combination according to claim 1 in which said lock includes at least a pair of angularly spaced projections extending radially beyond a rear portion of said simulated ammunition and in front of a rear portion of said gun in which said simulated ammunition is held.

3. A combination according to claim 2 in which said projections are displaceable to be drawn within an outer surface of said simulated ammunition.

4. A combination according to claim 3 in which said projections are separately actuatable for withdrawal within the outer surface of'said simulated ammunition and in which each of said projections extends from an angularly displaceable cam surface.

5. In a gun having a bore, a breech block pivoted to said gun for closing said bore, a first firing pin and an extractor carried by said breech block, simulated fixed ammunition for insertionfin said bore when said breech block is open, as'ubcaliber tube within said simulated fixed ammunition, a door pivoted to and within arear end portion of said simulated ammunition for closing said subcaliber tube when. subcaliber ammunition has been inserted in said tube, a second firing pin mounted within said door and arranged to be operated in response to movement of said first firing pin for firing subcaliber ammunition in said tube, an extractor for subcaliber ammunition, said last-mentioned extractor being carried'by said door, and a pivotal mounting for said door, the pivotal'mounting for said breech block being widely displaced angularly from the pivotal mounting for said door, the combination therewith of the improvement for avoiding the danger of-the breech block being moved toward a closed' position when said inner door is not closed, said improvement including a spring in cooperation with' said'inner door and with said simulated ammunition whereby after'a round of subcaliber ammunition has been inserted in said tube and the inner door released, that door is moved to a closed position out of the way of'closing movement of the breech block.

6. A gun having a breech block, an extractor carried by the breech block, mechanism whereby said breech block may be opened and closed, a round of simulated ammunition for insertion is said gun, a subcaliber tube within-said simulated ammunition, a door closing a rear end'of said tubejane'xtractorcarried by said door, a projection from" said-door of a length to extend into cooperation with said'extractor carried by said breech block whereby on opening said breech block said door is at least partially opened and any subcaliber ammunition may be at least partially extracted from said tube.

ReferencesCited in the file of this patent UNITED STATES PATENTS mime h. Wanner,

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